The sociological approach to economic action

Reading one classic paper by Mark Granovetter one sees how much we need the sociologist approach to economic action, far less naïve that the economists'. Two examples here:

To say, as Williamson does, that reliance "on internal promotion has affirmative incentive properties because workers can anticipate that differential talent and degrees of cooperativeness will be rewarded" (1975, p. 78) invokes an ideal type of promotion as reward-for-achievement that can readily be shown to have only limited correspondence for existing internal labor markets (...).
(Granovetter 1985:499)

(...) to avoid the the functionalims implicit in Williamson's assumption that whatever organizational form is most efficient will be the one observed. Before we can make this assumption, two further conditions must be satisfied: (i) well-defined and powerful selection pressures toward efficiency must be operating (...)
(Granovetter 1985:503)

References

Granovetter, M. (1985). Economic action and social structure: the problem of embeddedness. American Journal of Sociology, 91(3):481-510.
Williamson, O. (1975). Markets and Hierarchies. New York: The Free Press.

Study of predictors of taxi times at BCN Barcelona-El Prat Airport

Citation

Valenzuela-Arroyo, M., Lordan, O., Sallan, J. M. (2014). Study of predictors of taxi times at BCN Barcelona-El Prat Airport. 2014 ATRS World Conference. KEDGE Business School, Bordeaux, France.

Abstract

PURPOSE
This study develops a model to predict taxi in and out times at Barcelona-El Prat Airport. The model includes a set of variables that take into account the aspects that can affect taxi times, such as control areas, operation hours, type of aircraft, and others.

METHODOLOGY
The study has been carried out using airport’s daily operational data for the months of June, July and August 2013. After filtering the information, several linear regression models have been built which provide a predicted value of taxi times as a function of the predictors taken into account.

ANTICIPATED RESULTS
The area predictors combined with the hour of operation explain more than the 75% of variance of taxi times. Also, predictor models show that taxi times are greatly dependent on the type of operation.
The taxi in model has a stronger predictive power than the taxi-out model. Taxi-in accounts for 76% of variance and the mean error of residuals is 0.48 min, while the same values for taxi-out model are 45% and 2.16 min, respectively. The reason to be of these differences is the uncertainty produced by waiting times at runway headers in taxi out models, a variable that cannot be controlled.

KEYWORDS
Taxi Times, Linear Regression Model, Predictor, Barcelona-El Prat Airport

A study of pooling of repairable parts inventory between operators

Citation

Lopez-Gracia, N., Lordan, O., Sallan, J. M. (2014). A study of pooling of repairable parts inventory between operators. 2014 ATRS World Conference. KEDGE Business School. Bordeaux, France.

Abstract

PURPOSE
The purpose of providing availability inventory service is to maximize aircraft utilization by keeping spare units ready to be installed whenever and wherever needed. Since the size of the fleet supported by the spare repairable components inventory is the most important driver, we model the closed-loop inventory system in which component failures are Poisson distributed and the repair times at the service facility are exponential.

METHODOLOGY
 The method is based on Palm’s theorem for recommending a repairable operative inventory for a fleet and the model estimates parts demand during a certain period. In this research, we develop an inventory model for a repairable parts system which is shared by different operators in order to quantify the advantages of managing a “pool” inventory instead of private inventories for each customer.

ANTICIPATED RESULTS
Analysis of key parameters suggests that to improve the availability of the system with repairable spare parts, the supplier should improve the components repair facility, rather than the base stock level.

KEYWORDS
Inventory pooling, Component reliability, Repair facility, Poisson distribution

Analysis of robustness of alliance route networks

Citation

Lordan, O., Sallan, J. M.; Simo, P., Gonzalez-Prieto, D. (2014). Analysis of robustness of alliance route networks. 2014 ATRS World Conference. KEDGE Business School. Bordeaux, France

Abstract

PURPOSE
This study analyzes the robustness of the three major airline alliances (Star Alliance, oneworld and SkyTeam) route network to unintended errors and intentional attacks. Robustness is assessed in two ways: with an edge-betweenness based vulnerability scale, and with the evolution of the size of the giant component as a function of number of disconnected nodes.

METHODOLOGY
Network robustness is assessed in several ways. First, it is proposed a normalization of a multi-scale measure of the vulnerability in order to compare the performance of networks with different sizes. Second, several adaptive strategies are proposed to minimize the size of giant component with a given fraction of disconnected nodes. Together with other approaches found in the literature, a node selection criterion based on network efficiency is introduced. Finally, it is described a new procedure -the inverted adaptive strategy- for sorting the nodes in order to anticipate the breakdown of a network.

ANTICIPATED RESULTS
Results show that Star Alliance has the most resilient route network, followed by SkyTeam and oneworld. Besides, the inverted adaptive strategy based on the efficiency criterion -inverted efficiency- shows a good performance to break networks, similar or even better than the adaptive strategy based on node betweenness.

KEYWORDS
Airline alliances, route networks, robustness, airport closure.

Transformational leadership and organizational commitment: mediating role of leader-member exchange

Author

Imen Keskes

Supervisors

Jose M Sallan, Pep Simo

Defense date

1st October, 2014

Abstract

The thesis of Imen Keskes is a theoretical and empirical study of the relationship between transformational leadership (TL) and organizational commitment (OC). These two concepts are examined as multidimensional constructs and are empirically tested within a French speaking population. The main objective of this study is to examine the mechanisms through which dimensions of TL influence different forms of OC by testing the possible mediating role of leader member exchange (LMX). The present thesis consists of six chapters:

The first chapter introduces the concepts of TL, OC and LMX and the motivation for the research. It provides a brief summary of previous scientific work on the topic and it outlines the purpose and specific objectives of each chapter.

In the second chapter, a study and discussion of the relationship between leadership styles and OC  dimensions is carried out. An extensive literature research is performed in order to understand leadership and OC as well as the relationship between these two concepts. Although there is considerable research which suggest that TL is positively associated with OC in a variety of organizational settings and cultures, there is little empirical research focusing on the precise ways in which style of leadership impacts employee OC. Some critics about previous empirical and theoretical studies are presented and a number of areas for future research are developed.

In the third chapter, the English TL Questionnaire (TLQ) is translated into French using a back-translation technique. The validity and reliability of this instrument within two samples of French speaking populations (Tunisia and France) is tested. Internal consistency is assessed using Cronbach alpha coefficient. The construct validity is verified using the exploratory and confirmatory factor analysis. The results support a four-factor model of TLQ which consists of vision, supportive leadership, intellectual stimulation and personal recognition. These findings have shown adequate psychometric properties and have provided preliminary support for the construct validity of the proposed French version of the TLQ.

In the fourth chapter, the English OC Questionnaire (OCQ) is translated into French and the validity and reliability of this instrument within the two samples of  French speaking population is tested. The results have supported a 4-factor model of OCQ of the original questionnaire. These findings have shown adequate psychometric properties and have provided preliminary support for the construct validity of the proposed French version of the OCQ.

In the fifth chapter, some models that take into account the diverse dimensions of TL and the different forms of OC are proposed and tested by examining the role of LMX as a mediator between them. To verify the models, two types of validity tests are considered: the convergent validity and the discriminant validity. To test the direct hypothesis, the significance of the beta parameters in the structural models is assessed. To test the mediation hypothesis, two methods are used: Baron and Kenny method and a the comparison of nested structural models. The results confirm the significance of the proposed models. These findings are important since previous research did not test these variables together.

Finally, the last chapter summarizes the contribution of the thesis. The possible directions of further research work are also discussed in brief.

Thesis contents

Robustness of airline alliance route networks

Citation

Lordan, O., Sallan, J. M., Simo, P., Gonzalez-Prieto, D. (2014). Robustness of airline alliance route networks. Communications in Nonlinear Science and Numerical Simulation, 22, 587-595.
http://dx.doi.org/10.1016/j.cnsns.2014.07.019

Abstract

The aim of this study is to analyze the robustness of the three major airline alliances’ (i.e., Star Alliance, oneworld and SkyTeam) route networks. Firstly, the normalization of a multi-scale measure of vulnerability is proposed in order to perform the analysis in networks with different sizes, i.e., number of nodes. An alternative node selection criterion is also proposed in order to study robustness and vulnerability of such complex networks, based on network efficiency. And lastly, a new procedure – the inverted adaptive strategy – is presented to sort the nodes in order to anticipate network breakdown. Finally, the robustness of the three alliance networks are analyzed with (1) a normalized multi-scale measure of vulnerability, (2) an adaptive strategy based on four different criteria and (3) an inverted adaptive strategy based on the efficiency criterion. The results show that Star Alliance has the most resilient route network, followed by SkyTeam and then oneworld. It was also shown that the inverted adaptive strategy based on the efficiency criterion – inverted efficiency – shows a great success in quickly breaking networks similar to that found with betweenness criterion but with even better results.

Study of the robustness of the European air routes network

Citation

Lordan, O., Fernandez, V., Sallan, J.M. and Simo, P. (2014). Study of the robustness of the European air routes network. 4th International Conference on Logistics, Informatics and Service Science (LISS 2014). University of California – Berkeley (USA).

Abstract

The aim of this study is to analyze the robustness of the European civil European air transportation network from the perspective of the theory of complex networks. This study is based on analyzing the behavior of the network when its nodes (airports) are removed either by random errors or by deliberate attacks. The calculation of network statistical indicators as degree and betweenness distribution reveals that the flight flow network has the small-world characteristics and scale-free property. The selection of nodes on deliberate attacks is based on four centrality criteria: degree, betweenness, pagerank and eigenvector. This study aims to contribute to the understanding of the logistics network of European commercial flights, analyzing its strengths and weaknesses.

Conference presentation

This post of the Vicenc Fernandez website contains a video of the presentation at the LISS conference

Robustness of the air transport network

Citation

Lordan, O.; Sallan, J. M.; Simo, P.; Gonzalez-Prieto, D. (2014). Robustness of the air transport network. Transportation research part E: Logistics and transportation review, 68:155-163
http://dx.doi.org/10.1016/j.tre.2014.05.011

Abstract

This paper presents a methodology for the detection of critical airports (those whose isolation would cause the largest losses in network connectivity) in the global air transport network (ATN), based on simulating an attack on selected ATN airports using different adaptive selection criteria. The performances of several node selection criteria are compared, together with a new criterion based on Bonacich power centrality. The results show that most critical airports can be detected with an adaptive strategy based on betweenness centrality. The detection of such airports may help the development of contingency plans to develop an appropriate response to any airport closure.

Antecedentes de enviar un manuscrito a una revista científica

Citación

Sunyer, Silvia; Sallan, Jose M; Simo, Pep; Trullas, Irene (2014). Antecedentes de enviar un manuscrito a una revista científica. Ponencia presentada en la 4ª Conferencia internacional sobre calidad de revistas en ciencias sociales y humanidades (CRECS 2014). Madrid, 8-9 de mayo.

Abstract

Enlace al abstract de la ponencia

Presentación

Enlace a la presentación de la ponencia

Study of the topology and robustness of airline route networks from the complex network approach: a survey and research agenda

Citation

Lordan, O., Sallan, J. M., Simo, P. (2014). Study of the topology and robustness of airline route networks from the complex network approach: a survey and research agenda. Journal of Transport Geography, 37:112-120.
http://dx.doi.org/10.1016/j.jtrangeo.2014.04.015

Abstract

Communication via air routes is an important issue in a world organized around a web city network. In this context, the robustness of network infrastructures, e.g. air transport networks, are a central issue in transport geography. Disruption of communication links by intentional causes (e.g., terrorist attack on an airport) or unintentional (e.g., weather inclemency) could be crucial for countries, regions and even the airlines affected themselves. Policymakers and the management of airlines and alliances should be able to reduce the effects of such interruptions in order to ensure good communication through air transport (i.e., maximize the robustness of their network at a reasonable cost). The literature review of the study of air transport route networks through an analysis of complex networks has highlighted a lack of contributions to the study of the topology and the robustness of such networks which contrasts, with advances undertaken for other transport networks or communication systems. This survey suggests areas in which research should be undertaken, based on the existing literature in other areas and from three different perspectives: global route networks, airline alliances, airlines and airports so as to help towards a better understanding of air traffic and, therefore, to be able to assess the potential damage of any airport being inoperative for a continent, country or airline.

Equacions estructurals amb lavaan

Resum

L'anàlisi d'equacions estructurals és una tècnica per avaluar models amb relacions complexes entre variables (path analysis), amb variables observables i variables latents. Un cas especialment interessant d'aplicació és l'anàlisi factorial confirmatòria, que permet avaluar la validesa de constructe d'escales de mesura. En aquest article es presenta el paquet de R lavaan, que permet avaluar amb facilitat models d'equacions estructurals. Es reporta informació sobre la sintaxi del model, així com de les possibilitats del paquet.

Enllaç a UPCommons

http://hdl.handle.net/2117/22726

Airline route networks: A complex network approach

Author

Oriol Lordan

Supervisors

Jose M Sallan, Pep Simo

Defense date

14th April, 2014

Abstract

Communication via air routes is an important issue in a world organized around a web-like city network. In this context, the robustness of network infrastructures, e.g. air transport networks, is a central issue in transport geography. Disruption of communication links by intentional causes (e.g., terrorist attack on an airport) or unintentional (e.g., weather inclemency) could be a serious drawback for countries, regions or airlines. Policymakers and the management of airlines and alliances should be able to reduce the effects of such interruptions in order to ensure good communication through air transport, that is, to maximize the robustness of their network at a reasonable cost. The literature review of the study of air transport route networks through complex networks has highlighted a lack of contributions to the study of the topology and the robustness of such networks, which contrasts with advances undertaken for other transport networks or communication systems. The literature survey suggests areas in which research should be undertaken, based on the existing literature in other areas and from three different perspectives: global route networks, airline alliances and airlines. The aim of this research is to develop a better understanding of air traffic and, in particular, to be able to assess the potential damage of any airport being inoperative for a continent, country or airline. This thesis analyzes the topology and robustness of three proposed levels of study characterized by different units of analysis: global route network, airline alliances route network and airlines route network. The different levels do not only represent networks of different magnitudes in number of nodes (airports) and links (routes), but also represent different approaches. In Chapter 2 robustness of the global air transport network (L1) has been analyzed and criteria based on Bonacich power centrality has been presented in order to assess attack vulnerability of complex networks. One of the outcomes of this study will be a list of the most critical airports for the vulnerability of the entire air transport network. In Chapter 3 robustness of alliances route network (L2) will be assessed comparing the robustness of the three major airline alliances (Star Alliance, oneworld and SkyTeam). To perform this analysis, one new node selection criterion based on the efficiency of networks and one new method of assessing vulnerability will be presented. This analysis will lead also to a comparison of the robustness of the three alliances. Finally, in Chapter 4 robustness of 10 FSCs and 3 LCCs route network (L2) will be analyzed. The studied FSCs belong to the different airline alliances showed in Chapter 3 thus allowing the comparison among levels. This chapter outlines a comparison of the differences in robustness between FSCs and LCCs. In Chapter 5 a summary and discussion of conclusions obtained for each level will be carried out.

Thesis contents

The complete text of this thesis can be dowloaded at the TDR repository in the following link: http://www.tdx.cat/handle/10803/144526

Study of the evolution of routes operated by an airline going into bankruptcy: the case of Spanair

Student

Cristina Alemany

Supervisors

Oriol Lordan / Jose M Sallan

Defense date 

11th Abril, 2014

Abstract

The aim of this project is to analyze the competitive dyamics that evolve when an airline goes bankrupt. The cease of operations of the bankrupt airline gives an opportunity to the rest of airlines to increase the market share of the routes covered by the airline. If the bankrupt airline belongs to an alliance, these routes may be covered by other members of the aliance, competitors or airlines operating on a point-to-point basis.

This project analyzes in depth the case of Spanair, an Spanish airline went bankrupt on January 2012. The route portfolio of the company of the period January 2010 - January 2012 is considered for analysis. Results shows that LCCs (Vueling and Ryanair) and FSC from onewold (Iberia) and SkyTeam (Air Europa) absorbed the market share left by Spanair. Other companies from Star Alliance absorbed a fraction of the international routes of Spanair, but none of the domestic routes. Currently Star Alliance has a weak position in Spain, since there is no local airline in this alliance.

Online discussion forums with embedded streamed videos on distance courses

Citation

Fernandez, V., Simo, P., Castillo, D., Sallan, J. M. (2014). Online discussion forums with embedded streamed videos on distance courses. Journal of Technology and Science Education, 4(1):25-38.
http://dx.doi.org/10.3926/jotse.91
http://www.jotse.org/index.php/jotse/article/view/91

Abstract

Existing literature on education and technology has frequently highlighted the usefulness of online discussion forums for distance courses; however, the majority of such investigations have focused their attention only on text-based forums. The objective of this paper is to determine if the embedding of streamed videos in online discussion forums generates educational dialogue and consequently the feedback that students need in a Management Accounting Course. The findings suggest some interesting issues, such as: students prefer text answers except in complex questions, and videos never replace text commentaries and explanations, but rather complement them.

Study of the Robustness of the European Air Routes Network

Citation

Lordan, O., Florido, J., Sallan, J. M., Fernandez, V., and Simo, P. Gonzalez-Prieto, D. Study of the Robustness of the European Air Routes Network (February 26, 2014). Available at SSRN: http://ssrn.com/abstract=2401696

Abstract

The aim of this study is to analyze the robustness of the European civil European air transportation network from the perspective of the theory of complex networks. This study is based on analyzing the behavior of the network when its nodes (airports) are removed by random attacks and deliberate attacks. The selection of nodes on deliberate attacks is based on four criteria: degree, betweenness, pagerank and eigenvector. This study aims to contribute to the understanding of the logistics network of European commercial flights, analyzing their strengths and weaknesses. The calculation of network statistical indicators as degree and betweenness distribution reveals that the flight flow network has the small-world characteristics and scale-free property.

Organizational commitment vs focal and discretionary behaviours

Citation

Simo, P., Enache, M., Sallan, J. M., & Fernandez, V. (2014). Relations between organizational commitment and focal and discretionary behaviours. The Service Industries Journal, 34(5), 1–17. doi:10.1080/02642069.2014.871534

Abstract

The purpose of this paper is to analyse the relations between organizational commitment dimensions and two focal and discretionary behaviours (intention to stay and organizational citizenship behaviour). Drawing on a sample of 310 Spanish employees of small services firms, this research reveals that in contrast to recent findings that detected a non-linear (inverted U-shaped) relationship between continuance commitment and intention to stay, the form of the relationships between organizational commitment dimensions and the proposed outcomes is linear rather than non-linear. Furthermore, when dividing continuance commitment into two sub-components, the research results indicate that the dimension associated with commitment based on few existing employment alternatives is significantly, negatively and linearly related to intention to stay and organizational citizenship behaviour. This suggests that the three-component model of organizational commitment suffers from a conceptual inconsistency, which is further discussed.